Vacuum-discharger for lower tensions



A. FARANDA.

VACUUM DISCHARGHR FOR LOWER TENSIONS. APPLICATION FILED JAN- 4, 1919.

1 35 55 8126, mmm (F at 5 192% h a/e'mZ w:

fi/Zeria 2 52 raw all PATENT OFFICE.

ALBERTO IAEANDA, 0F MILAN, ITALY.

' vAcUUM-Disormnom r03. LOWER, TENSIONS.

To all whom it may concem:

Be it known that I, ALBERTO FARANDA, engineer, subject of the King of Italy, residing at Milan, Via Ponte Seveso 35, Italy, have invented certain new and useful Improvements in Vacuum Dischargers for Lower Tensions, of which the following is a specification.

The present invention relates to a safety discharge device. for low potentials working with a proper measurement of pressure and without being subject to troubles arising from its working or from mechanical causes.

This object is attained by the use of metal electrodes, the mass and the surface of which are reduced to a minimum, and the disposition of which, as well as the mechanical connection effected by the aid of an interposed insulating substance, is such as to render impossible any change of position or of the relative distance between the electrodes.

The accompanying drawing represents, by way of example, two difi'erent types of construction of the device; the type represented in Figure 1 must be essentially regarded as anexplanatory diagram, while the type shown in Fig. 2 represents a construction designed to afford a perfect workmg. 1

The safety discharge of my invention consists, as shown in the drawing, of two annular metal electrodes A A (preferably of aluminum or silver) provided with stems B B and electrically connected to platinum filaments C C sealed in a glass bulb D containing a highly rarefied gas. 'The said Specification of Letters Patent.

Patented Oct. 5, 1920.

. Application filed January 4, 19l9. Serial No. 269,645.

filaments are then attached to small external metal caps E E which are electrically connected to the line to be protected. A small cylinder F of insulating and incombustible material, such for example as mica, is inserted in the two annular electrodes and serves to hold them in position.

The sparking distance can be exactly determined either by placing the electrode rings in positions inclined to each other (see Fig. 1), or by providing the opposite faces with pins or points arranged upon alternate sectors (as shown in Fig. 2).

I claim as my invention:

A safety discharge device for low potentials, consisting in its entirety of the combin-ation of two small annular metal electrodes placed opposite each other; a single small cylinder of insulating and incombus- .tible material inserted through both annular electrodes and on which they are immediately held in position and at a given distance apart; a glass bulb containing a highly rarefied gas and in which the electrodes are arranged, the said bulb being provided at each end with a small metal cap forming contact with the adjacent electric conductor to be protected; and platinum wires at opposite ends of the bulb connecting said caps to the internal electrodes and sealed in the glass of the bulb; substantially as described.

In testimony whereof I afiix my signature.

ALBERTO FARANDA.

Witnesses:

D. H. PASQUALE CORRANO, Bnnvmrr RADMONDO. 

